Oil filter



Dec. 26,` 1944.

y J. M. LEvxER OIL FILTER Original Filed Feb. 23, 1937 2 Sheets-Sheet l0 a 2 .wJlJ

f EE Dec. 26, 1944.y v y J, M, LEVYIER 2,365,766

OIL FILTER Original Filed'Feb. 25, 1937 2 Sheets-Sheet 2 SWW/nm c/zz MQLevier.

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Patented Dec. 26, 1944 Jaim M. Levier, Anaheim, Calif., aasignor tooscar H. Levier, Arlington, Calif.

Continuation of application Serial No. 127,307,

February 23, 1937.

This invention relates to filtering means and relates more particularlyto filters for clarifying liquids such as oils, etc. vA general objectof this invention is to provide a simple, practical and particularlyeffective lter. l

This application is ledas a continuation of and a substitute for myapplication for United States Letters Patent Serial No. 6127,30?, ledFebruary 23, 1937.

Another object of this invention is to provide Y a lter that Viseffective in removing solid matter particles and other material fromlubricating oils,

h Y remove all accumulated Wax, and the like, to con-- for example, fromthe lubricating oils employed in the crank cases of internal combustionengines.

, The oil filters usedin connection with internal.

combustion engines are of three general types,

namely:

This application April 10, 1939, Serial N0. v267,130

11 claims. (el. 21o- 133)y moved from the case and more thoroughlycleaned by subjecting it to a vsolvent bath, or the like, to

dition -it for further extended use. The improved iiltering element-provided by the present invention may be cleaned from time to time by,introducing a' cleaning medium or `iiuid under pressure into the lterand'may be removed from the'case after extended use and after repeatedcleaning by the fluid` pressure to be thoroughly cleaned andreconditioned for further extended use.A The ease and simplicity withwhich the filtering element may be cleaned and the dura-v bility of theiiltering element promotes the gen- (1) The discardable type that isdiscarded m its entirety when it becomes clogged, to be replaced by anew or replacement filter;`

(2) The removable cartridge type comprising a permanent-housing and acartridge that is discarded and replaced when clogged; Y

(3) The 'repackable type, including a permanent housing and a specialfilter mass or filter cartridge that requires special skillfulrepacking. This last named type (3) lter is expensive and its efficiencydepends upon the care and skill with which it is repacked. In the threegeneral types of lters referred to factory replacements are necessaryand the filters are a constant source of expense. v

Another object of this invention is to provide an improved oil lter thatremains operative and effective for a long period and is adapted to beeasily and quickly cleaned and reconditioned for continued, fullyeffective operation without detachment or dismantling and ,withoutthelreplacement of parts. f

Another object of this invention is to provide an oil iilter of thecharacter mentioned embodying a novel eflicient filtering element thatsubjects the liquid or oil to a progressive filtering action toassuretheltration or removal of particles of dust, metal, carbon, dirt, etc.of various sizes.

Another object of thisinvention is to provide a iilter of the charactermentioned embodying a illtering element "that is long wearing and thatis adapted to be cleaned from time to time With-` out removal from thebody or case by introducing air, steam, or otherfiuid. under pressureinto the filter tube and after repeated cleaning by the fluid pressurethe filtering element `may bevreterior of the iiltering element servesto free the eral economy in the use of the iilter and assures thethorough filtering of the oil throughout greatly extended periods ofoperation of the lter.

Another object of this .invention is to provide a filter of thecharacter mentioned embodying a filtering element comprising a tubularspirally wound fabric strip having sections Whose mesh is graduated fromthe periphery of the element inwardly to its inner wall, with the meshreduced in an inward progression, and the lter further includes meansfor causing a distributed now or movement of the oil inwardly throughthe filtering element to be subjected to the progressive ltering actionof the graduated fabric mesh and has means for introducing a cleaningfluidV vunder pressure to the interior of the filtering sure action andto drive out and wash away the accumulated particles of filtered-outmaterial, driving such material outwardly through the expanded mesh andthe expanded separated layers of the ltering element, 'I'he liquid oroil being nltered flows or moves inwardly through the superimposedlayers of fabric whose mesh vis graduated so that 'the suspended matterinthe liquid is effectively ltered out and the air, steam, or otherfluid under pressure admitted to the inmatter thusvcollected by thefabric and drives the particles outwardly through the graduated fabricmesh of outwardly increasing size to effectively remove such particlesfrom the filtering element.

Another object oftheinvention is to provide an oil lter in which therate vof filtration may be regulated and related to the rate of oilow tomaintain the rate of filtration in excess of the rate of contamination.

Another object of the invention is to provide a lter of the charactermentioned 'embodying means for visibly indicating the condition of theVfiltering element throughout the operation of the filter.

Another object of this invention is to provide a lter of the charactermentioned that includes novel means for removably securing the filteringelement in its liquid passing and filtering position in such a mannerthat the liquid or oil cannot leak through the ends of the unit andcannot channel through the filtering element.

A further `object `of this invention is to provide an oil filter of thecharacter mentioned including simple, effective means for conducting theliquid or oil to and from the filter case which means includes a by-passsystem for by-passing liquid around the filter when the liquid issupplied in excess quantity or under excess pressure and when the owthrough the filter is diminished or cut off because of the accumulatedmatter in the filtering element and during reconditioning and replacingof the filtering element.

Another object of this invention is to provide a filtenof Ithe characterreferred to in which the filtering element may be formed of inexpensivematerial to be discarded after a-.suitable period of use or may beformed of more expensive and more effective material to .be durable andcapable of repeated reconditioning and cleaning.

Another object of this invention is to provide a filter of the charactermentioned that is simple and compact and that is easy to install andrecondition.

The various objects and features of my invention will be fullyunderstood from the following detailed description of typical preferredforms and applications of the invention, throughout which descriptionreference is Imade to the accompanying drawings, in which:

Fig. 1 is a central longitudinal detailed sectional view of the improvedf'llter of the present invention with certain of the fiuid conductingelements in side elevation. Fig. 2 is a transverse detailed l.sectionalview taken substantially as indicated by line 2-2 on Fig. l. Fig. 3 isan elevation view or plan view of the filtering element in a fiatcondition. Fig. 4 is an enlarged fragmentary edge elevation of a portionof the filtering element and Fig. 5 is an enlarged fragmentarylongitudinal detailed sectional view illustrating a modified form ofliquid-receiving tube.

The improved lter of the present invention may be said to comprise,generally, a body or casing I, a core or tube 6 in the casing I forreceiving the filtered liquid, a ltering element 49 around the tube 6,means for conducting fiuid to and from the casing I to be filtered bythe element 49 and means for introducing air or other fluid underpressure to the tube 6 to remove accumulated foreign matter from thefiltering element 49 and the casing I.

The body or casing I contains the filtering element 49 and serves tosupport the various other parts of the device. In the constructionillustrated the casing I is an elongate cylindrical course, fluidtightand pressuretight except for the fluid handling connections to be laterdescribed.

The core or tube 6 forms a. carrier or support for theV filteringelement 49 and serves to receive the filtered liquid or oil from thefiltering element. The tube 6 is preferably arranged centrally andlongitudinally in the casing I-and is provided with circumferentiallyand' longitudinally spaced ports or perforations for admitting orpassing fiuid. In the particular construction illustrated in thedrawings the upper end of the tube 6 is secured to the casing cover 3 sothat the tube may be removed from the casing to gether with the cover.`Brazing or welding may secure the tube 6 to the cover 3 as shown at 1.The tube 6 is preferably of substantial length and may extend downwardlythrough the casing I to have its lower end in spaced adjacent relationto the bottom 2. A baiile or disc 8 is provided on the lower end of thetube 6. The disc 8 may be secured to the tube 6 in any selected manner.In the construction illustrated brazing or welding 9 serves to attachthe disc 8 to the lower end of the tube 6. A central longitudinalopening I2 in the disc 8 communicates with the lower end of the tube 6.

In accordance with the invention longitudinally spaced flanges I6 and Ilare provided .on the tube 4l. The flanges I6 and I1 are spaced asubstantial distance apart being on the lower and upper end portions ofthe tube, respectively. The flanges I6 and I1 are annular or cylindricaland are preferably of the same diameter. As will be later described, theflanges I6 and I1 serve to carry the filtering element 49 and to closethe ends of the element. The fluid passing perforations of the tube 6are confined to the central portion of the tube, that is, to the portionof the tube lying between the spaced anges IB and I'I.

The filtering element 49 is an important feature of the invention. Theelement 49 is provided to remove or filter out particles of solid matterand other iilterable matter from the oil or liquid handled by thedevice. In accordance with the invention the .filtering element 49operates to' subject the liquid to a stage filtration or a progressivefiltering action and is capable of .being expanded and freed of a largeproportion of the filtered-out material by air, steam or other fiuidunder pressure supplied to its interior. The filtering element 49 is atubular member or assembly arranged around the tube 6 in substantiallyconcentric relation thereto to filter or act on the liquid passing fromthe casing I inwardly into the tube E.

In accordance with the invention the filtering element 49 is in thenature of an elongate strip or assembly of fabric spirally wound orwrapped to form a tube. The fabric strip comprising the filteringelement 49 is sectional embodying por tions or sections of fabric ofdifferent mesh. In the particular embodiment of the inventionillustrated the filtering element 49 includes three sections 50, 5I and52. The fabric sections 50,l 5I and 52 are preferably connected orsecured together, for example, they may be stitched together so that thefilteringv element forms a continuous elongate fabric strip. Thecharacter and relationship of the fabric sections 50, 5I and 52 of theelement 49 are important. The element 49 is wrapped or wound so that thesection 50 provides its inner Wrappings or convolutions and the section5I forms its intermediate convolutions and the section A52 forms itsouter convolutions. The sections 50, 5I and 52 may be substantiallyequal in lengthI although this relationship may be variedas desired.Thehfabrio sections V50, I` and 52 are formed of fabric fof-graduatedmesh, the sections 50 `being formed loffabric; of

fine mesh, `the section 5I being formed offabric of somewhat coarsermesh, andthe section 52 being formed of fabric of` a still coarser mesh@The filtering action of the sections 50, 5I and `52 -depends lto someextent upon the nature ofA the fabric weave, the fabric texture andthenaturel of the fibers of the fabric, and where I herein describe thefabric as being aflne, intermediate, and coarse mesh it is tobeunderstood that the term mesh is to be construed as meaning not e Themesh of the sections 50, 5I "andl 52v is so graduated that the spirallywound sectionslarranged in the progression described above effectivelytrap or iilterout praoticallyall the foreign .matter contained` intheoil` Vor liquid passed through theltering element 49. The lteringelement 49 is o f substantiailength to have a considerable number ofconvolutions, for example; in a typical installation itA may have fromto 35 layers or convolutions. The filtering element 49 is reeled orwound to-be .of such external diameter that it may freely enter thecasing I with suitable clearance.` In accordance with the invention thefiltering element 49 is ofsuch width that it projects beyond the anges-IIr and I'I and in the construction illustrated the width of thefiltering element substantially equals the length of the tube 6.

Where it is intended to repeatedly cleanuthe filtering element 49 by theactionlof fluid under pressure admitted to the tube 6 `and by repeatedwashings of the lteringelement in suitable sol- Y vents it is (preferredto construct the sections 50,

5I and 52 of Y woolen fabrics, for example, Aof pureA woolen fabrics orfabrics containing but a. very smallpercentage of fibers other thanwool. Where the filtering element 49 is to have a shorter life and isintended for earlier replacement the fabric sections 50, 5I and 52 maybe formed of cotton fabricsV which may be suitably treated to beresistant to the action of the acids, etc. inthe oil being handled. y e

The invention provides novel and veffective means forremovablysecuringthe filtering element 49 around the tube 6L The,A upperand .low-

l er edge or end portions of the tubular-element 49 project beyond theflanges I'I and I6 and bindings 53 of `wire or strong cord are `arrangedabout t these projecting portions to secure the element 49 in its`operative position. .'I'he bindings Y63 preferably eachcomprise a`plurality :of wrappings tightly drawn about the element 49.y Thebindings 53 serve to tightlycompress the filtering element49Yagainst-the peripheries of` the flanges IB and I'I andrcompress theprojecting end portions of the element49 so` that the layers orvconvolutions are in tight or close relation. It is preferred to arrangethe bindings 53 in offset relation to the flanges I6 and I1to hold themajor portion of the filtering element 49 under a suitable tension sothat it retains its tubular shape. The filtering element 49 ispreferably proportioned `so that its upper end is at or in contact withthe cover 3 and so that its lower end engages the disc 8. With thisarrangement the cover `3 and the disc 8 constitute supports for thefiltering element 49 and prevent endwise distortionof the element. Thebindings 53 wrapped about the end portions of the fllteringelement 49 asdescribed above, effective prevent the entrance or excess leakage of theoil or liquid through the ends of the element into the tube 6 so thatthe oil is' obliged to flow radially inward through the filteringelement to the tube and prevent the air, steam or other cleaning fluidunder pressure from escaping through the ends of the filtering elementsothat the cleaningfiuid must pass outwardly through the fabricflltering'element. The

bindings 53 are easily applied and` aresuch that they may be readilyremoved to `of the element 49 from the tube 6.-

permit removal .The invention provides means at theinterior and exteriorof the filtering element 49 to stabilize and support the element and toassure the effective voperation of theelenient. Metal or wire screening48 is wrapped or arranged about the tube '6 to form a supportfor theinterior of Vthe filtering element 49 and vto prevent the inner'convolutions of the element from entering and .,clog`ging 'theperforations Vof vthetube 6. The

screening 48'may be spirally wound aboutl the cover Il` and surroundsthe portion of the tube between-the flanges I6 and Il. If desired thesceening 48 may be suitably permanently associated with the tube 6andthe inner layer'of the elementmay be removably secured to thescreening.` A perforated tubular liner I5 may be provided in the casingI to surround the filtering element 49. The liner VI5; looselyts'thecasing I and may rest on its bott'om'2. A plurality of longitudinallyspaced transversely arranged spacers 55l maybe provided on the'outer endY portion of the coarse fabric section 52` to be on theperiphery oftherel'erment 49 when the same is assembled or wra'pp'ed.`v The spacers55 may consti'tutelengths of rope stitchedor otherwise secureditoythe'illter section 52. The spacers 55 serve to space the filtering'element 49 from the liner I5" and the casing I and are effective inholding the outer convolutions of the element against excessive andirregular expansion when y, uid under pressureis forced outwardlythrough the element toclean the same. Spacing rods 5 4 may. be insertedbetween the liner I5 and the Vperiphery of the filtering element 49 toassist the spacers 55. The liner I5, the spacers 55 and the spacing rods54 are not always essential inevery application of the invention. Themeans for conducting the liquid or oil to or from the lter casing I isoperable to receive the fluidV under pressure from the lubricantcirculating system vof an engine, or the, like, 4and conduct it, to thecasing I and to ,receive the filtered oil orlliquid from Athe tube 6andreturn Vit to the engine. `In--accordance with the invention the oil,or liquid is delivered tothe interior of the casing vI to Vflow or passthrough the filtering element 49 and then leave the casing from theinterior of the element 49 or the tube. in the drawings 30 designates apipe conducting the liquid or oil from the lubricant circulatory systemv of an. engineor the like, and 3l designates a pipezforreturningthecleaned `or filtered oil to the engine. The liquid conducting means ofthe invention includes interconnected conduit assemblies, one assemblyreceiving the oil from the pipe blies may, of course,v be

33 and deliveringit to the casing I, and the other receiving thefiltered oil from the tube 3 and conducting itto the pipe 3l. Theseconduit assemvaried considerably in construction and arrangementVwithout 'departing from the invention. In the case illustrated the firstnamed conduit assembly comprises asuitable elbow 3l having one armthreaded in an opening 35 in the upper portion of the casing I. Amanually operable valve 33 is connected with the other arm of the elbow34 and a T 28 is secured to the delivery pipe 30. Acheck valve 32 isinterposed between the valve 33 and one arm I will term a `nippleIII-extending through `an opening II in the casing bottom 2 and havingits upper portion threaded in the opening I2 of the disc 3. Anenlargement or head I3 is provided on the exposed cuter end of thenipple I and a washer or gasket I4 is arranged between the head I3 andthe casing bottom 2. The head I3 may be polygonal to be convenientlyturned by a wrench. It will be seen that the head I3 may be turned tothread the nipple I0 so that the tube 6 and the cover 3 will be drawndownwardly to tightly and securely seat the cover on the casing I.Reverse threading of the nipple 'In of course loosens and frees theassembly of the tube 6 and the cover y3. d end of the nipple III toreceive the filtered oil from the opening 41 of the nipple and piping44-45--43-.42 connects the elbow 48 with one arm of a T729 provided onthe return pipe 3|. A union 4I is connected in the piping just mentionedto facilitate the assembling of the piping and to facilitate the easythreading of the nipple I0. A manually operable valve 4I) is connectedbetween the pipe section 42 and the T 29 and is adapted to be closed toput the pipe 3i out of communication with the interior of the filter. Acheck valve 39 is connected or interposed be- I of the T 23. Thecheckvalve 32 may be a ball l pressure in the nlter ordue to closing of thevalve 33 the ball31 is unseated and the liquid under pressure flows fromthe pipe 33 to the pipe 3i. When this occurs the check valve 33 preventsthe fluid under pressure from flowing to the nipple I3 and tube 3. Inlarge filters the by-pass valve 33 may be set or ,adjusted so that asubstantial proportion of the oil is normally by-passed from the pipe tothe pipe directed through the filter. In' such an installation the saidresidual flow is great enough to overcome or nullify the contaminationof the oil by the normal engine operation. The valve 33 may be partiallyclosed or set to regulate the rate of oil flow through the filter andthus obtain the correct balance between the filtration rate and v theby-.pass rate.

bleeding air 4from the casing I, cross the operation of the filter isinitiated.V The valve f The invention provides means for indicating thepressure in the casing I so that the condition and operation of thefiltering element 49,may be ascertained without removing the elementfrom the casing I. A pipe or nipple 58 is threaded in an opening in theCover 3 and carries a cross 51. The cross 51 in turn carries a pressuregauge 56. The gauge 5B operatesY to indicate the pressure within thecasing I. One arm of the cross 51 carries a manually operable bleedervalve for 51, etc. when is normally closed. Another arm of the cross 51carries a relief valve or safety valve 59 deg signed to open andyrelieve the pressure in the casing I in the eventl excessive ordangerous.

It is an important feature of the invention that means is provided forcleaning4 or reconditioning the filtering element I9 while the same iswithin An elbow I6 `is` threaded in the lower tween the valve 40 and theT 29. The valve 33 may be a ball check and operates to prevent a returniiow or a reverse flow from the pipes 30 and 3| to the tube 6 and casingI.

Theinlet and discharge piping systems Just described are connected by aAvalved by-pass to allow all or a portion of the liquid to by-pass thefilter when the filtering element 49 becomes clogged or-when thevalves33 and 40 are closed or when the oil is supplied to the ilter at a highrate cr excessive rate. This lily-pass comprises a frelief valve orby-pass` valve connected between the T 28 and the T 23. The valve 36 maybe any suitable type' of valve capable of providing for the ilow ofliquid from the pipe 30 to the pipe 3| when a predetermined pressurebuilds up in the p ipe 30 and the communicating system. In the simple'construction' illustrated the valve 33 includes a ball 31 seatingupwardly or toward thev T 2l and a spring 3l urging the ball to itsclosed position. The spring 38 may be set or formed to urge the ballclosed under any selected force. When pressure builds up in the line V30due to ing the filtering element 49.

, cleaned. A pressure gauge 64 is the casing I. This means includes anipple or pipe 62 threaded in an opening in the cover 3 to communicatewith the tube 6. A T fitting 63 is provided on the' pipe 62 and a pipefrom the fitting. The pipe $5 is controlled by a manualvalve 51.A Thevalve 61 is adapted to receive air or other fluid under pressure forclean- As shown in Fig. 1, a pipe or line 66 leads to the valve 61 todeliver the air or other fluid under pressure to the valve. The line 6 8may be connected with a source of air under pressure, steam pressure, orother fluid under pressure when the filtering element is to bepreferably connected with the fitting 63 to indicate the pressure beingapplied to the filtering element 49 when the same is being cleaned orreconditioned. The gauge 64 also indicatesthe pressure in the tube 6during operation of the filter.

' or discharge cock 6I communicates with the lowclosing of .the checkvalve 32 by reason of `back 15 er end of the casing I to discharge thematerial blown or washed from the filtering element I3 and to dischargethe vcleaning iiuid. The operation of cleaning and -reconditioning thefiltering element 49 will be more fully described.

Fig. 5 illustrates a modified construction embodying a tube I3 which maybe substituted for the tube 6 describedabove. jThe tube I8 is perforatedto pass fluid to and from the surrounding filtering element I3. Hollowenlargements or flanges I3 and. are provided on the opposite ends of thetube I3. The flanges lI! and 2li have the same function as the flangesI8 and Ildescribed above, that is, the end or edge portions, of theelement 43 are supported on the flanges I3 Aand'ZII being Vtightlyconfined against the flanges by the bindings 53. In practice the angesI3 and 20 may be integral Withthe. tube' 3l and the residual oil flowis' that, the pressure becomesV extends A drain cock I8. The flanges I9and 2U taper outwardly to have reduced outer end portions. The outer endthe under side of the bottom 2,. Itwill .be seen that threading ofthenut 25 against the gasket' 25 and bottom 2-ldraws the tube I9 and thecover 3 downwardly and the nut may be threaded to tightly secure thecover 3 to the casing I.

In the use or` operation `-of the improved filter of this invention theliquid or oil from the pipe r39 discharges into the casing I from theelbow -34 and the clarified or filteredoil returnsfthrough the nipple I9and the piping assembly 46--45-V cleaning fluid. The valve 6'Imay beopened to admit the uid under pressure to the tube 6 and the gauge 64may be read to determine the pressure on the fluid thus admitted to thetube 6; The cleaningfluid flows out through the perforated tube 6 andthe wire mesh or metal screening 46 to the filtering element 49. Thecleaning iiuid under pressure in the interior of the tubular filterelement 49 expands the filtering 44-43-42 to the pipe 3|. The iicwpf,liquiderv oil through thefilter may be continuous. Liquid or oildischarged into the casing I `from the elbow 34 nows or passes inwardlythrough the 'filtering Velement 49 and the metal screening 49 to thetube 5. During the passage of'the oil through the outer section 52 ofthe element 4I!` the'larger particles of .solid matter and foreignmaterial are caught or ltered out by the fabric section. As

the oil continues inwardly through theelement. 49 smaller particles arefiltered out by the secr tion 5I and the smallest particles are filteredout by theinnermost section 59. Thus the liquidlor oil is subjected `toa stage filtrationor a, progressive flltration action. `It has been.found that the filtering element 49 effectively clarifies the cil,

y operating to `remove practically .all suspende element and'tends tofree or separate Vthe several convolutions of the element. The spacers55 and thespacing rods 54 assure a distributed expension oftheperipheral portion of the element 49 and hold the element out ofcontact with the linerv I5. The cleaning fluid under pressure pass- \ingoutwardly through the filtering element 49 frees or loosens thelaccumulated particles lilteredfrom the oil and carries these particlesoutwardly into the casing I. It will be seen that the smaller particlesin the fine meshfsection 50 readily pass outwardly through the largermesh .sections 5I and '52 when loosened or freed by the cleaning fluidunder pressure. In alike manner the somewhat larger particles freed fromthe section `5I readily pass outwardly through the coarse meshv section52. The foreign matter driven from the ltering element 49, as justdematter from the' oil. IA certain` amount of the solid mattermay'settie from the oil into the lower portion ofthe casing I to betrapped below the disc 8 and some of the foreign material caught by thefiltering element 49 may fall into the lower portion of the casing.During the normal opervation of the filter the gauge 56 indicates' thepresscribed, is free to discharge through the openedV In a like mannerthe solid matter that cock 5I. may'have settled in the lower portion ofthe casing I discharges from` the cock 6I together with the cleaningfluid.' Whenthe'ltering element 49 has been effectively cleaned thesource of cleaning fluid under pressure'ls disconnected from the line66. In the event a liquid cleaningfagent has been used it is desirableto connect a source of airfunder pressure with the line 66 to blow allresidual cleaning liquid from thefllter to preventcontamlnation anddilution ofthe oil. The

valve' 61 .and the cool: 6I are now closed. The.

^ valves 33 and 49. are then opened to re-establish sure in the casingiand the gauge 64may indicate the pressure on the clarified oil in thetube 6.

By comparingr the readings of the lgauges 56 and 64 the pressure dropresulting from thefiltration may be determined. When the filterreachesthe normal operating temperature at the start of `itsoperationthe differential in l'pressure as indicated by the gauges 56 and 64 maybe quite small and'equals, the pressure lrequired to force the oilthrough the filter. As the dirt accumulates on thefiltering element 49the pres-` sure differential increases. When the gauge 56 indicatesapressure equal tothe pressure setting of the by-pass valve 36 Vthefilter is no longer in` l effective operation and the filtering element49 should be cleaned.

After a period "of operation'it may be` neces--y sary to cleanvorrecondition the filtering element` 49. In accordance with theinventionthis econditioning may be performed without isthe figw of fluid or oilthrough the lter and the bleeder valve 60 may be momentarily opened tobleed all air from the casing vl. The above described method of cleaningthe filtering element 49 :is easily and quickly carried out and iseffective in conditioningthe element for further use. The cleaning`element v49 may be repeatedly cleaned in the manner lust described.y

When it becomes desirable or necessary to give the filtering element 49a more thorough cleaning to remove waxy substances, etc. the valves 33and 49 are closed so that the oil by-passes the filter and the union 4Iis disconnected to permit the outward threading of the nipple IIIl tofree the tube 6 and the cover 3. 4 The cover 3 carrying the tube 6 andthe filtering element 49 is removed `or disengaged from the casing I andthe bindings 53 are loosened so that the filtering element 49 may beunwound. The filtering element 49 may then be thoroughly cleaned in anymantling the filter and without removingthefilt tering element 49 fromthe casing l. To clean or `recondition the filtering element 49while inthe casing I the valves v33 and 40 are rst closed to stopflow of liquidor oil through the` filter.

With the valves 33 and 40 closedthe `oilfiows froml the pipe 39 to thepipe 3I through the bypass valve 39. Following the closing of the valves33 and 44I) the drain cock 6I is opened and a source of fluid under`pressure is put intoccmmunication with theline 66. The fluid employed``to clean or recondition the filtering element 49 i may be air, steam,water, or any other selected selected manner, for example, it may becleaned by a solvent, or the like. The tube 6 and the 1 screening 49 maybe thoroughly cleaned and, if desired, the interior of the casing I andthe other parts of the apparatus may be cleaned.

The reconditioned and cleaned filtering elementV 49 may be rewound andsecured in place by the bindings 53. In the event the element 49requires replacement, the new or replacementelement 49 `may bewoundabout the tube 6 and secured in place by the bindings 53. The filter isthen reassembled and put into use in the manner de-v scribed above.Whenthe filtering element 49 is formed 'of a good grade woolen `fabricit may be meaning afilteringmaterial fabric capable of extension,elongation or expansion when subjected t'o the action of fluid pressure.as distinguished from' wire fabrics, and thellike, which are capable oflittle or no extensionor expansion by such action.

Having described only typical preferred forms and applications of myinvention, I do not wish "to be limited or restricted tothe specicdetails herein set forth, but wish to reserve to myself any variationsor modifications that may appear the filtering element to back wash andthereby expand and clean the element.

4. In a filter of the character described, a casing, a tubular filteringelement in the casin comprising a spirally wound strip of extensiblefabric,the inner convolutions of the element bey ing of a finer meshthan the outer convolutions,

to those skilled in the art orfall'withiril the scope of the followingclaims:

Having described my invention, I claim z, g 1. A re-useable filteringelementfor use in a filter for arresting solid matter particles carriedby oil or other liquids comprising acontinuous strip ofnon metallicextensible fabric graduated in mesh in a longitudinal direction andspirallyw'ound intotube form to have vthe portions of nner mesh-constitute its inner convolutions and the portions of coarser mesh formthe outer convolutions so that liquid forced inwardly through the woundstrip is subjectedto progressive stage filtration and so thatthe-arrested solid matter particles are stored in the strip..the' wound'strip being expansible when subjectedito theac'tion of fluid pressureadmitted to its interior so that said stored particles are freed 'ford'slodgement by said admitted internal fluidpressure. i

2. In a filter for arresting'solid matter par'.- ticles carriedby oil orother liquids, a perforate supporting tube, an elongate tube ofextensible woven fabric spirally wound around the tubeA to form afiltering element for liquid forced inwa'rdly tothe tube, the stripcomprising a section of said inner convolutions readily being drivenout-l l means confining the end portions of the element to prevent thepassage of fluid therethrough and supporting the major intermediateportion of the element for expansion by internal fluid pressure, meansfor conducting fluid to the casing to pass inwardly through thefiltering element to be filtered thereby, means for conducting thefiltered iiuid from the interior of the filtering element, and means forintroducing a cleaning fluid under'pressure to the interior of thefiltering element to expand theelement'and pass-outwardly through theelement to drive and wash out-theflltered-out material from the element,the finer particles of said material trapped in wardly through theexpanded element.

' 5.`In a filter of the character described, a casing, a tubularfiltering 'element in the'casing comprising a spirally wound strip offabric, a

support extending through the tubular element,

annular enlargements on the support spaced 1nwardly from each end ofthe'element, the ele- I ment having end portions extending beyond theenlargements to prevent the passage of fluid through the end portions ofthe element, said 'l' bound end portionsof the element being free of thesupport so that the bindings maintain an axial tension on the elementand compress the coarse mesh constituting the outer portion of theelement, a section of finer mesh constituting the intermediate portionof the element, and a sec-- tion of finer mesh than the second namedsection constituting the inner portion of the element, at least one ofsaid sections continuing.

element against the' margins of the enlargements, `means for conductingfluid to the cas-g ing to filter-through the element to its interior',

andmeans for conducting the filtered fluid away from the interior of theelement. i 6. In a filter. a casing, a.y longitudinal support 'normallycontracted element, means for ad tion in' which the large particlesiarearrested by the coarse mesh section, the particles of inter-l mediatesize are arrested by said second named section and the smaller particlesare arrested by the last namedsection, and means coniiningthe ends ofthe filtering element and allowing expansion of the other parts of theelement by fluid under pressure introduced into the tube for the jparticles `retained in purpose ofdriving out the the element.

3. In a filter of the character described', a casing, a re-useabletubul'arltering elementin g the casing comprising a spirally vwoundstrip of `extensible non metallic fabric, the strip being graduated inmesh so that its outer convolutions are of coarser mesh than its innerconvolutions, means for supporting the filtering element so that itsmajor portion lis expansible by internal fluid pressure, meansconducting fluid to the casing to pass inwardly through thelteringelement v to be subjected thereby to stage filtration, meansconducting the filtered fluid from the interior of the filteringelement, and means for introducing a cleaning fluid under pressure tothe interi?? Gf mitting fluid under pressure to the interior of theelement to expand the element and dislodge the accumulated filtered-outmaterial therefrom, and means spaced from the normally contracted'element for preventing the periphery of the-element from contacting thewall of the casing when said.r

Afluid pressure expands the element, the last named means spaced partsbetween the periphery of the ele ment and the wall of the casing.

comprising circumferentially '7.` A filter comprising a casing,` aremovable closure for one end of the casing, a perforated tube carriedby the closure and disposed in the casing, an outlet nipple connectingthe tube with the opposite end of the casing to hold the closure inplace, spaced flanges on the tube, a screen sur'- rounding the portionof the tube between said flanges, -illtering material wound around thescreen with its end parts extending over saidY flanges to have freeportions beyond the flanges;

bindings tightly compress the filtering material against the flanges. 1

'e pand the element.

8. A iilter comprising a casing, a removable closure for one end of thecasing, a perforated tube carrie? Vbythe closure and disposed in thecasing, a p ate on the lower end of the tube. an

outlet nipple threadedly engagedv with the plate l ment on the supportcomprising a spirally wound fabric strip, the mesh of said strip beinggraduated insize longitudinally of the strip with the coarsest mesh attheperiphery of the strip and the finest mesh at the interior of thestrip, means for. conducting fluid to and from the casing to filterinwardly through said element so that it is subjected tostagefiltration,v means for ad-` fabric strip member spirally wound aroundlaid tube, the mesh of said strip being Igraduated in sizelongitudinally of the strip with the coarsest mesh at the periphery ofthe strip and the finest mesh at the interior of the strip, a perforated'liner for said casing, spacers between said liner and the fabricfiltering member, means for admitting iiuid to Athe casing to filterinwardly through the graduated strip member, and means for admitting airunder lpressure `into the perforated tube whereby'airv may be directedoutA wardly through the filtering member for dislodging sediment'adhering to the outwardly increasing mesh of the memberl` 11. In afilter, a casing' open at its upper end. a cover for theopen end ofsaidcasing, a perforated tubeextending from said 'cover longituv d inaly inthe casing in axial relation thereto with its lower: endspaced-'fromvthe bottom of Vthe casing, anoutlet nipple extendingthroughthe bottom of the casing and having threaded connection with thelowerend of the' tube.' co1- f lars .encircling said tube adjacent upper andmitting fluid` under pressure to the interior of the element to expandthe element and' dislodge the accumulated filtered-'out material fromthe expanded element. and means holding the periphery of the elementspaced from the wall of the casing whereby lsaid iliuid pressure may ex-10. In a iilter, a casing, a perforated=tube exy tending longitudinallyin said casingran outlet nipple leading from Vthe lower end of said tubethrough :the bottom. of saidk casing,v an elongate lower ends thereof,screening surrounding the tube between the collars, a strip of fabricwound about the tube and screening `to provide a tubu- Ilar filteringmember ofA fabric having its ends projecting beyond the collars, andbinding means for the projectingv portions of the tubularfiltering'member ilrmly securing the iiltering member inplace withportions thereof *in close contacting engagement with: margins of thecollars. v l I yJOHN imam N

